import java.util.Scanner;

public class 计算圆 {

    public static void cir(double r){
        Scanner sc=new Scanner(System.in);
        double s=Math.PI*r*r;
        double c=Math.PI*2*r;
        System.out.println("圆的面积为"+s);
        System.out.println("圆的周长为"+c);
    }
    public static void main(String[] args) {

        cir(4);
    }


}
